Telephonic transmitter



B. S. COHEN.

TELEPHONE TRANSMITTER.

APPLICATION FILED DEC.31|1919.

1,356,190. Patented Oct. 19,1920.

PATENT OFFICE.

JEER'IRAIVI SYDNEY COHEN, TWICKENHAM, ENGLAND, ASSIGNOR TO THE RELAY AUTOMATIC TELEPHONE COMPANY, LIMITED, OF LONDON, ENGLAND.

TELEPHONIC TRANSMITTER... i

rename.

Specification of Letters Patent.

Patented Oct. 19, teen.

To all whom it may concern:

Be it known that I, BERTRA SYDNEY COHEN, a subject of the'King of Great Britain, residing at 9 Lebanon Park, Twickenhain, Middlesex, England, have invented a new and useful Improvement in Telephonic Transmitters, of which the follow- 111 is a specification.

his invention relates to telephonic transmitters of the type ad ted to be placed against the throat of the user and to be operated by the vibrations in the throat instead of as is usual by the waves of sound issuing from the users mouth, and the object of the invention is to provide a transmitter of this type which shall be more efli-- cient than those hitherto proposed and shall especially be unaflected by external noises such as those produced by machinery in the neighborhood of the user.

According to this invention the'part of the transmitter which is placed against the users throat is rigidly connected to and encrophone 4 of the usual carbon granule type tirely supported by a diaphragm; which preferably forms part of the case of-the instrument. According to the invention also the transmitter is mounted upon one end of a .short stout rod or tube the other end of which carries a telephone receiver. With this arrangement the movement of the .mierophone parts is greater than if the transmitter is held in the hand or by means of a pliable strap or the like.

The invention is illustrated by the accompanying drawing, Figure 1o which is a section of a transmitter. while Fig. 2 shows a transmitter mounted on a support which also carries a receiver;

1 is a block of non-conducting material in a central hole in which is a metal socket 2 into which is inserted a screw 3. A miis centrally mounted within a cylindrlcal casing 5, the middle of the flexible end of which is nipped between the head of the screw 3 and the face of the socket 2. In order to. prevent the screwvfrom becoming unscrewed a pin 6 may be inserted in holes drilled in theheadof the screw, the end of the case and the socket 2. To the head of the screw 3 is secured an insulating disk 7.

. This bears against a nut 8 attached to the center of the microphone 4. Itw'illbeseen that the block 1 and the flexible end of the casing 5, which end acts as the main diap ragm, are only in contact at their centers and that the vibrations in the throat of the user are transmitted to the microphone 4-, the damping of the vibrationsof the main diaphragm being reduced to a minimum;

The microphone is mounted on a bridge 9 of insulating material fixed across the back oi the casing 5.

10 is a cylindrical cap which fits tightly around the casing 5 and incloses the whole. The transmitter is mounted on one end of a short stout rod or tube 11 the other end of which carries a receiver 12, so that the user by grasping the rod 11 can hold the transmitter to his throat and the receiver to his ear.

What I claim is l. Ina telephone transmitter, a casing, a flexible diaphragm supported therein, and a block adapted to be placed against the throat of the user and supported only by the center of the diaphragm.

'2. In a telephone transmitter, a casing, a flexible diaphragm supported therein, a block adapted to be placed against the throat of the user, and a screw connecting the block to the center of the diaphragm.

3. In a telephone transmitter, a casing,

a flexible diaphragm supported therein, a

block adapted to be placed against the throat of the user and supported only by the center of the diaphragm, a microphone, and means for conveying the vibrations of the diaphragm to the microphone.

4. In a telephone transmitter, a casing, a flexible diaphragm supported therein, a

throat of the user, a screw connecting the block to the center ofthe diaphragm, a m crophone, and means for conveying the v1- brations of the diaphragm to the micro-' phone.

5. In a telephone transmitter, a casing,

block adapted to be placed agamst the a flexible diaphragm supported therein, a

6. In a telephone transmitter, a casinghaving a flexible end; a blockof non-conducting materiaha tapped metal socket therein, a screw engaging the socket and nipping the flexible end of the casing between its head and the socket, an insulating Washer on the head of the screw,a microphone contained Within the casing and a member supported by the microphone and resting against the washer.

In testimony that I claim the foregoing 10 as my invention I have signed my name this eighth day of December, 1919.

BERTRAM SYDNEY COHEN. 

